Hikers walk the trail at Coyote Wall in the Columbia River Gorge National Scenic Area. Getting outside is good for your body and mind, studies show. / Allen Thomas, AP

by Kim Painter, Special for USA TODAY

by Kim Painter, Special for USA TODAY

Sunburn, bug bites, Lyme disease, poison ivy. Sometimes it seems the great outdoors is just one big health hazard.

So it's easy to forget that communing with Mother Nature is actually good for us, at all ages and in all sorts of ways.

"We grew up as a species being outdoors," and our minds and bodies thrive there, says Victoria Maizes, executive director of the Arizona Center for Integrative Medicine at the University of Arizona-Tucson.

"There's risk in nature. That's one of its attractions," says Richard Louv, an author and advocate who has written several books on connecting with nature. But, he says, staying inside is risky, too. "Pediatricians are telling me they are not seeing many broken bones in kids anymore. What they are seeing are repetitive stress injuries from using computers and mice." Obesity is, in part, another side effect of the indoor life, he says.

Robert Zarr, a pediatrician in Washington, D.C., who goes by the nickname Dr. Nature, is so convinced that outdoor time is essential to good health that he writes "park prescriptions" for his patients.

"It has been very well received" and has increased physical activity and outdoor time among children in his practice and others, he says.

Don't have a doctor who writes nature prescriptions? Write your own this summer. You and your family just might:

â?¢ Exercise more. Studies show people who start an exercise routine outdoors are more likely to stick with it than those who exercise inside, Maizes says. "It's a different experience from walking on a treadmill," she says. Outdoor exercise also might be more effective, Louv says. "When you are hiking a trail or building a treehouse, you are working on core strength," something adults and kids skimp on in indoor workouts, he says.

â?¢ Stress less. "Being outside seems to tap into the relaxation side of our nervous system and does it in as little as five minutes," Maizes says. While more studies are needed, there's evidence that outdoor time helps relieve symptoms of anxiety and depression, Zarr says. "People just feel better. Happiness increases when you are outside."

â?¢ Improve attention. One study at the University of Illinois found that kids with attention deficit hyperactivity disorder were able to concentrate better after a walk in a park. "Just a little bit of contact with nature helps kids focus," Louv says.

â?¢ Make more vitamin D. Sun exposure prompts your body to make the vitamin, which is essential for bone health and has other benefits. So some health experts urge people to spend 10 or 15 minutes outside every couple of days without sunscreen. But the American Academy of Dermatology disagrees: It says you can get your vitamin D from foods or supplements without raising your risk of skin cancer.

â?¢ Sleep better. Get some morning sunlight each day, and you will sleep more soundly at night, says the National Sleep Foundation. Morning light can be especially helpful for someone with an out-of-sync body clock - as many jet-lag veterans know.

â?¢ See better. "Over the past 30 years or so, rates of nearsightedness have been increasing," and studies strongly implicate the decline in time children spend outside, says David Hunter, chief of ophthalmology at Boston Children's Hospital and a clinical spokesman for the American Academy of Ophthalmology. Exposure to outdoor light may help the eye develop properly, he says. And practice using distance vision may matter, too, he says. (But kids and adults should still wear sunglasses, he says.)

Louv says that when we spend time outside, we simply "feel more alive." That's more than enough reason, he says, to open the front door. "What parent wants their child to be less alive? What adult wants to be less alive?"

Of course, you also want to feel safe. So the usual precautions apply:

â?¢ Use sunscreen (all the time if you follow the advice of dermatologists). You want one with broad spectrum protection and an SPF of at least 30.

â?¢ Use insect repellents as needed for the bugs near you. And check for ticks after walks in wooded areas.

â?¢ Choose sunglasses that block 99% to 100% of ultraviolet light. For the best eye protection, get a wraparound style.

â?¢ Dress for the weather, but with an eye toward protection from the sun, insects and poisonous plants. That means hats, long sleeves, pants and sometimes gloves (when clearing brush or gardening).